Terms in this set (12)
The Cell Theory
-All living organisms are composed of one or more cells and they perform all life functions.
-Cells are the basic unit of structure and function in an organism
-Cells can only come from the reproduction of existing cells.
Metabolism is the sum of life sustaining chemical reactions such as movement, growth and repair. It manages the energy and material resources in a cell.
Response to Stimuli
Organisms respond and react to changes in their environment.
Increase in living matter, in multicellular organisms this means making more cells.
The process through which organisms make more of their own kind. This is necessary for the survival of the species. Parent cells copy and pass genetic information to their offspring.
Asexual: Genetically identical
Sexual: Genetic variation in offspring
The elimination of excess waste and products of metabolism.
The maintenance of a constant internal environment in response to changes in the external environment.
Cells take in and use substances from their environment which they use for energy and other life processes.
Exceptions: Skeletal Muscle
It is made out of muscle fibres that are enclosed in a membrane but they are much larger than most cells and contain hundreds of nuclei.
Organisms with only one cell carry out all the functions of life.
Importance of the Surface Area to Volume Ratio
The surface area to volume ratio is a factor that limits cell size. This is because the surface area controls how fast materials can enter and exit the cell and the volume controls the rate at which those materials are used. Therefore, if a cell becomes too large, its volume increases and its surface area decreases which means that materials are utilised at a rate faster than they are exchanged and the cell is unable to take in essential materials and excrete waste materials fast enough.
How to Calculate Magnification
Actual Size = Measured Length/Magnification
Magnification = Measured Length/Scale Bar Label